This invention relates to a construction machine which is provided with an operating lever alongside an operator""s seat and which can be suitably applied, for example, to a hydraulic excavator or the like.
Generally, in the case of construction machines such as hydraulic excavators or the like, console devices are usually provided on right and left sides of an operator""s seat, each console device having a manual operating lever, for example, for manually controlling the operation of a hydraulic excavator.
More specifically, prior art hydraulic excavators of this sort usually includes a vehicle body with an operator""s seat to be occupied by an operator and an entrance opening providing an access to the operator""s seat, and console devices to be operated by an operator sitting on the operator""s seat. And said console device is constituted by a console including an operating lever vertically pivotally supported on the vehicle body at a lateral side of the operator""s seat for manipulation by an operator, a biasing member for urging the console to swing back toward an upturned position from an operating position, an entrance gating lever provided at one side of the console and pivotally switchable to and from an entrance blocking position and an open position, and a lock mechanism provided between the vehicle body and the console to disengageably engage therewith and adapted to be switched into an unlocking position by the entrance gating lever from a locking position holding the console in the operation position (For example, Japanese Laid-Open Utility Model Publication No. H6-85456).
In this connection, for example, the console is pivotally supported at its rear portion so that its front portion can be turned up and down about the pivotally supported portion between an upturned position and an operating position. When the console is in the operation position, an operating lever is located in a fore position by the operator""s seat, so that an operator of the hydraulic excavator, who is seated on the operator""s seat, can manipulate the operating lever in a natural posture, for example, for driving a front working mechanism.
When an operator on the operator""s seat intends to get down from the machine, the console is swung back into an upturned position as the entrance gating lever is shifted to an open position. As a result, the console is turned in an obliquely rearward direction together with the operating lever, permitting the operator to get down from the operator""s seat and get off the machine through a passage which is now opened in front of the console.
Further, the entrance gating lever is linked with a safety change-over valve which functions to open and block communication between a hydraulic pump and a hydraulic circuit. When the entrance gating lever is shifted to a blocking position, the safety change-over valve is closed to suspend pressure oil supply to a vehicular drive motor and a rotating motor of the hydraulic excavator as well as pressure oil supply to hydraulic cylinders of the front working mechanism, preventing erroneous or spontaneous activation of hydraulic actuators while an operator is away from the machine (e.g. as disclosed in Japanese Laid-Open Patent Publication No. H4-30032).
In this instance, a lock mechanism is constituted by a locking lever which is pivotally supported on the side of a vehicle body through a pin member, for example, on a lower front portion of the console, and a lock pin which is provided on the side of the console and arranged to be brought into and out of engagement with the lock lever. While the hydraulic excavator is in operation, the lock lever of the lock mechanism is held in engagement with the lock pin. As a result, the console is locked in an operating position against a biasing action of a tension spring.
On the other hand, when the entrance gating lever is manipulated by an operator who is going to get down to the outside from the operator""s seat, the lock lever on the side of the vehicle body is turned about the pin member and disengaged from the lock pin. As a result, the console is released from a locked state and raised into un upturned position by the biasing action of the tensile spring.
In this regard, according to the above-mentioned prior art, the lock lever of the lock mechanism is pivotally supported on the side of the vehicle body, and arranged to be brought into and out of engagement with the lock pin on the side of the console. When the entrance gating lever is shifted by an operator, the lock lever is turned out of engagement with the lock pin, permitting the console to swing back into the upturned position under the influence of the biasing action of the tension spring.
However, the above-described rotary type lock lever has a base end portion pivotally supported on the side of the vehicle body simply through a single pin member, and in that state it is brought into and out of engagement with the lock pin on the side of the console. Therefore, when vibration, impact or other external force is applied to the console device, for example, it is very likely that staggering movements occur between the lock lever and lock pin or between the vehicle body and the lock lever, resulting in generation of noises or malfunctioning of the lock mechanism.
In view of the above-described problems with the prior art, it is an object of the present invention to provide a construction machine with a lock mechanism which is free of staggering movements even when an external force is applied thereto and which can retain a console stably in an operating position while the construction machine is in operation.
For solving the above-mentioned problems, the present invention is directed to a construction machine which basically includes a vehicle body having an operator""s seat and a entrance providing an access to the operator""s seat, and a console device to be operated by an operator who is seated on the operator""s seat, the console device including a console vertically swingably supported on the vehicle body in a position at one side of the operator""s seat and provided with an operating lever to be manipulated by the operator, a biasing member urging the console from an operating position to an upturned rest position, an entrance gating lever pivotally supported at one side of the console and pivotally switchable to and from a blocking position and an open position, and a lock mechanism for releasably locking the console to the side of the vehicle body, the lock mechanism being arranged to be shifted to an unlocking position by the entrance gating lever, releasing the console into an unlocked state from a locking position holding the console in the operating position.
According to the present invention, there is provided a construction machine which is characterized in that the lock mechanism of the console device comprises: support projections provided on the side of the operator""s seat and projected toward the console: a slide member supported by the support projections for back and forth sliding movements and provided with a notched groove at a fore end portion thereof: a locking projection provided on the side of the console and adapted to be brought into engagement with the notched groove when the slide member is shifted forward into the locking position and disengaged from the notched groove when the slide member is shifted rearward into the unlocking position: a biasing spring member provided between the vehicle body and the slide member and arranged to urge the slide member in a direction for engagement with the notched groove; and a link member connected between the entrance gating lever and the slide member and operative to slide the slide member in a rearward direction against the biasing spring in relation with manipulation of the entrance gating lever.
With the arrangements just described, when the slide member is in the locking position, the locking projection on the side of the console is held in engagement with the notched groove in the slide member by the use of the spring member, thereby locking the console in the operating position. When the entrance gating lever is shifted by an operator, the slide member is pulled by the link member to slide into the unlocking position. As a result, the locking projection is disengaged from the notched groove, releasing the console from the locked state and permitting same to swing back into the upturned position under the influence of the biasing member.
According to the present invention, the notched groove formed substantially in V-shape diverging toward its outer open end, so that the locking projection can be held in abutting engagement with opposite wall sections of the V-groove.
Further, according to the present invention, the notched groove is defined in the slide member by a substantially horizontal upper wall section, and a sloped lower wall section inclined downward in forward direction.
With the arrangements just described, at the time when the locking projection is disengaged from the notched groove by a horizontal sliding movement of the slide member and swung back into the upturned position along with the console, it can be smoothly disengaged from the notched groove along the horizontal upper wall section of the notched groove. Further, since the lower wall section is sloped downward in forward direction, the locking projection can be abutted against both the upper and lower wall sections of the notched groove.
Further, according to the present invention, the slide member is provided with a tapered surface along a fore end portion on the upper side of the notched groove for guiding the locking projection toward and into the notched groove.
With the arrangements just described, when the locking projection is swung downward toward the operating position along with the console, it is abutted on the tapered surface of the slide member and thereby guided toward and into the notched groove.
Further, according to the present invention, the slide member is provided with a slot extending substantially horizontally in a longitudinal direction thereof and in a position vertically offset from the notched groove by a predetermined distance, and the support projections are slidably received in the slot for sliding movements therealong.
With the arrangements just described, as the slide member is put in a forward or rearward sliding movement on the support projections which are slidably received in the slot, it can be smoothly moved to an stroke end substantially free of vertical staggering movements which are restricted by the support projections. In addition, since the slot and notched groove are provided in vertically offset positions, an external force which may be exerted on the slide member from or through the biasing member acts as a moment tending to hold the sliding member in abutting engagement with the support projections in a stabilized state.
Further, according to the present invention, a plural number of support projections are provided at one side of the operator""s seat at intervals in horizontal direction. Accordingly, as the slide member is horizontally put in a forward or rearward sliding movement, it can be supported by a plural number of support projections and moved smoothly free of vertical staggering movements.